Conversion of higher boiling hydrocarbons



April 16, 1940. A. E. PEW, JR

coNvERsIoN OF'HIGHER BOILING HYpRocARBoNs Filed Feb. l5. 1957 PatentedlApr. 16, 1940 UNITED STATES CONVERSION F HIGHER BOILING HYDROCARBONSArthur E. Pew,

Jr., Bryn Mawr, Pa., assignor, by

mesne assignments, to Houdry Process Corporation, Wilmington, Del., acorporation of Dela- Application February 15, 1937, Serial No. 125,687

11 Claims.

The present invention relates to the treatment Aof composite hydrocarbonmaterials, such as those occurring in or derived from petroleum, coal,shale or other source, natural or artificial, to produce therefromvaluable hydrocarbons suitable for useas fuel in internal combustionengines, including lower boiling hydrocarbons of the type of benzines,naphthas, gasolines, kerosenes andthe like. More particularly, it isconm cerned with the production of such lower boiling hydrocarbons fromhigher boiling hydrocarbons containing both clean, easily vaporizablematerial or distillate stock and diiiicultly vaporizable material of thetype of heavy distillation residues.

A number of pyrolytic or thermal processes for converting higher boilinghydrocarbons into lower boiling hydrocarbons are well known to the artand various systems differing from one another only in minor respectsare in common use. A 20 more recent development involves the catalytictransformation of hydrocarbons by a continuous process utilizing twoormore converters containing absorbent catalytic materlal which isperiodically regenerated or reactivated, preferably in situ, so thateach converter may be alternately on stream and in regeneration, asindicated, for example, in the copending application of Eugene J.Houdry, Serial No. 610,567, filed May 11, 1932, and issued as Patent No.2,078,247 on April 27, 1937. 'I'he pyrolytic systems produce usually,from fresh feed, a lower yield of high anti-knock motor fuel than doesthe catalytic system but appear to handle partially converted ortransformed material with reasonable facility. Because of this facility,many pyrolytic systems involve internal recycling of distillate stockshaving clean distillate or gas oil characteristics, obtained, usually,from fractionation of the con,- verted material or synthetic crudeleaving the re` action zone. 'I'he pyrolytic systems perform at greaterefficiency on distillates of the gas oil type than on residual materialsof the general type of those remaining from the distillation of crudepetroleum. When working on such residues it is often true that thepyrolytic systems can produce motor fuels of good anti-knock rating onlyunder severe operating conditions and at the cost of relatively lowyields of desired product with attendant high yields ofgas andunconverted residua. The motor fuel so produced sometimes containsrelatively large amounts of sulphurous compounds, because of thetendency of sulphurhydrocarbon'compounds to concentrate in residualstocks, and is therefore often quite difficult to rene. The highproduction of coke reduces (Cl. ISG-49) the time eiliciency of thesystem by requiring frequent shut-downs for removing the accumulatedcoky deposits. 'Ihe catalytic system, on the other hand, is best adaptedto operations where successive residues from transformed materialproduced in separate, distinct and successive catalyst crackingoperations or passes are segregated to provide charging stocks for theseparate and successive passes, usually effected at progressivelyAincreasing severity of reaction conditions. In general, this systemmakes its best product in the first pass or when transforming virgin orfresh feed. In the rst pass, it produces high yields of high anti-knockmotor fuels from residual stocks, as well as from distillates. The motorfuel is easily refined, regardless of the source and characteristics ofthe charge, and, in addition, the residue remaining after separation ofthe motor fuel from the transformed products or synthetic crude made inthe catalytic system is clean, has charactertstics and uses of a gas oilor distillate fuel oil and is suitable for use as a' charging stock to apyrolytic system,

One object of the present invention is to provide a unitary systemcontaining catalytic'and pyrolytic reaction zones disposed and arrangedso that the advantages of each type of zone are secured and thedisadvantages of each minimized or even avoided. Another object is toprovide for exibility of operation. Another object is to realizeeconomies of heat and of equipment. Other objects will be apparent fromthe detailed discussion which follows.

A concrete embodiment of the invention is set forth diagrammatically inthe accompanying drawing or flow chart.

The invention involves a pyrolytic or thermal reaction zone A, shownenclosed by a light full line, and a catalytic reaction zone, enclosedby a broken line, and indicated generally by reference character B, anda single fractionating zone containing fractionator I. The latter isconnected to a source of fresh feed and to both reaction zones A and Band functions coincidently and cooperatively with both reactions so as:

(1) To provide selected or segregated charging stock for each of saidzones, the selected charges comprising (a) One or more streams of cleanhigher boiling hydrocarbon distillates which are fed to ref action zoneA and (b) A still higher boiling fraction containing substantiallyallthe diflicultly vaporizable or residual hydrocarbons present in thefresh charge, which fraction is admitted to reaction zone B;

(2) 'Io receive and fractionate the reaction products or syntheticcrudes from both reaction zones, after such products have had removedfrom them substantially all material higher boiling then the charge tozone A or within the boiling range of the charge to zone B, and.optionally, a portion of the material within the boiling range of thecharge to zone A, so that,

(a) The selected or segregated distillate or distillates charged to zoneA may contain partially converted distillates of restricted andcontrolled boiling range as well as fresh or virgin stock, and

(b) The charge to reaction zone B is substantially free of partiallyconverted material; and

(3) To provide a stream of desired end point lower boiling hydrocarbonswhich comprises a blend of substantially all of such material which ispresent in (a) The fresh charge and (b) In the products from bothreaction zones A and B.

When it is desired to effect complete or substantially completeconsumption of fresh feed, the higher boiling material separated fromthe reaction products may be charged to reaction zone A along with or asan adjunct to the feed to that zone, or, the unitary system may beoperated to provide, in addition to the desired end point motor fuel,higher boiling materials of controlled amount and character and havingthe uses and properties of domestic and Diesel distillatefuels.

Referring more particularly to the drawing, fresh charge, which may be,for example, a whole crude petroleum oil or a derivative thereof, suchas a topped crude, or any blend or composite mixture of hydrocarbonscontaining both easily vaporizable and diillcultly vaporizable materialswhich may be made or may occur in refinery practice, is continuouslyadmitted to the unitary system by line 2 and conducted through thelatter to heater 3 wherein it is heated to distillation temperature andis then sent through line l to fractionating column I. Any desiredportion of the charge may be preheated in heat exchanger 5, located inline 2 and provided with a valved by-pass therearound. From fractlonatorI there is withdrawn one or more higher boiling side stream distillatefractions, as for example, a heavy naphtha by line 6, a relatively lightgas oil by line 1 and a relatively heavy gas oil by line 8, the heavyunvaporized residuum is withdrawn from fractlonator through line 9. Thedistillate fraction or fractions are conducted into reaction zone A bysuitable branch connections, such as those shown, while the distillationresidue withdrawn from fractionator I by line 9 is fed to reaction zoneB, in which zones the desired conversion takes place.

In some instances, as for example, when the fresh charge bearsrelatively large amounts of organic sulphur compounds and/or when itcontains unusually large amounts of diflicultly vaporizable or tarrynature, it is desirable to withdraw a long residuum from fractlonator iby line 9 containing substantial amounts of the higher boilingdistillate portions of the charge. Such practice facilitates handling ofthe residuum in reaction zone B and provides for reduction in thesulphur content of the desired reaction products. In such cases, heatexchangers or any other suitable equipment for effecting separation fromthe reaction products of material boiling within aiaaooa the boilingrange of the charge to zone B is operated to condense larger quantitiesof the synth'etic crudes. Such partial condensation may also beregulated so as to avoid recycling through reaction zone A of partiallyconverted material boiling within the boiling range of the heavierportions of the charge to that zone. To this end. the reaction productsissuing from the reaction systems may have removed from them componentsboiling within the boiling range of a portion or even all of the gas oilissuing from fractlonator I by lines 1 and/or 8 for the purpose ofimproving the conversion in reaction zone A and/or to provide stock forfuels capable of meeting a wide range of volatility specifications.

All lower boiling hydrocarbons of the desired end boiling point made inthe unitary system as hereinafter described and any of such hydrocarbonsintroduced thereinto with the fresh charge are withdrawn fromfractlonator I as a single stream or blend by overhead vapor line 23.This blend may be subjected to any desired treatment either before orafter condensation. When it is desired to effect direct condensation ofthe lower boiling hydrocarbons the vapor in line 23 may be condensed incondenser 24 and have fixed or incondensable gases removed therefrom inseparator 25 provided with gas outlet 26, hydrocarbon condensatewithdrawal line 21 and a connection 28 for removing condensed steam. Anydesired amount of condensate may be returned to fractlonator I by line29 to be used as reflux, while the remainder may be withdrawn from thesystem by line 30.

Pyrolytic reaction zone A may contain one or any desired number ofsystems of any known or desired type for effecting pyrolytic or thermalconversion of higher boiling hydrocarbons in the vapor phase, liquidphase or mixed phase, as for example, utilizing equipment and operatingconditions used in the pyrolytic conversion systems commonly known asCross, Dubbs, tube and tank, De Florez, true vapor phase, gyro,Holmes-Manley, etc. Three such pyrolytic systems are indicated in theaccompanying drawing, each comprising a cracking furnace 32a connectedby valved transfer line 33a to flash chamber or tower 34a which isprovided with a valved residue or tar Withdrawal line 35a and a valvedvapor outlet 36a. Each of the pyrolytic systems is selectively connectedto each of the lines 6, I and 8 by suitable manifolds and valvedbranched lines, shown, and to products vapor line I0 by valved vaporoutlet 36a.

Although the charge to pyrolytic zone A may be a single stream ofdistillate, in the interest of high yield of good quality product it ispreferable to separately convert a plurality of streams of distillateshaving restricted or relatively narrow boiling ranges under separate anddistinct operating conditions. It is particularly advantageous toseparately convert naphtha fractions and gas oil cuts for naphthasgenerally require more severe reaction conditions (high temperatureand/or pressure) than do the higher boiling gas oil cuts. Althoughpartially converted distiliates in line 20 may be mixed with one or moreof the gas oil cuts issuing from fractlonator I, it is preferable toseparately convert the partially converted distillate. The hydrocarbonscharged to any oi the conversion units or systems in zone A may besubjected to the action of temperatures within the range of 750 to 1200F. and pressures of from substantially atmospheric or slightly below to3000 iba/sq. in. gauge. or more, the

pressures and temperatures used in any given system being dependent uponthe type of system, and, to some extent, upon the source andcharacteristics of the charge thereto. 'I'he general tendencies aretoward: (1) slightly less severe operating conditions with higherboiling range characteristics and/or lower A. P. I. gravities of thecharging stocks; and (2) somewhat more severe operating conditions whenthe charge is comprised to substantial extent of partially convertedmaterial.

Pyrolytic systems usually provide suitable apparatus for effectingseparation of heavy unconvertible residues from the remaining and cleandistillate portions of the reaction products made in the system. Suchequipment often takes the i'orm of flash vaporizers which may effectreduction of such residues to coke or which may permit withdrawal of theresidues as liquid having con-1 trolled characteristics, which liquidmay be used as a residual fuel or for the starting material for roadoils or asphalts. Flash chambers 34a in reaction zone A are used forthis purpose. Each may be operated so that a heavy viscous tarry residueis removed therefrom by valved line 35a, or, in order to meet refinerydemands for more fluid residual oils, condensation of the heaviestportions of the vaporous reaction products in transfer line 33a may beeffected withthe aid,

if necessary or desirable, of a suitable coolingv iiuid which may, forexample, be admitted to lines 33a by valved inlets 33e. The resultingcondensate is withdrawn as part of the residue. In such instances, theremaining vapors often have an end boiling point within the boilingrange of the charge to zone A and can be conducted directly to vaporline I4 by means of manifold 31, shown selectively connected to vaporlines 30a.

Thus, each pyrolytic system is selectively connected to fractionator` Iand separator I3 by manifolds I0 and 31 respectively. When a cokingoperation is conducted in chambers 34a the distillates leaving zone Asometimes have boiling ranges which also permits by-passing of separatorI 3 by manifold 37.

In a preferred form of the invention, catalytic zone B conforms ingeneral to that disclosed in the aforesaid Patent No. 2,078,247, issuedto Eugene J. Houdry on April 27,V 1937, and that disclosed in UnitedStates Patent No. 2,031,600 issued to J. W. Harrison et al. on February25, 1936, and comprises: (1) a heater 38h of any desired type forreceiving and vaporizing a substantial part of the charge to zone A (2)one or more vessels or separators 39h connected to heater 38h forremoving any unvaporized material from the vapors produced in thelatter, these separators 39h being provided with vapor and tar outletlines 40h and 4Ib, respectively; and (3) two or more converters 42harranged in parallel and selectively connected to vapor line 40h by line43h and valved branches 44D. They are also connected to products line IIby valved branches h. Converters' 42h may be of any suitable type whichprovide reaction chambers containing a regenerative adsorptive orcatalytic contact mass of any desired type capable of promoting thedesired transformation. Preferably, the mass is of a slicious nature andis in comminuted or molded form, comprising, for example, molded piecescomposed essentially of a blend of silica and another metal oxide, suchas alumina. The blend may be of natural or artificial origin, includingcolloidal and precipitated gels and activated hydrosilicates of aluminaof a clayey nature. 'Good results are ob tained with a catalyst having aweight ratio4 of silica to alumina in the mass of 395:1, or more, andother characteristics as disclosed in the copending application ofEugene J. Houdry, Se-

rial No. 600,581, filed March 23, 1932 and renewed July 3, 1936 whichissued on May 4, 1937, as Patent No. 2,078,945. If desired, the contactmass may contain one or more suitable ingredients, such as metals ormetallic oxides, for aiding the transforming reactions and/or theregeneration of the mass by combustion of contaminants deposited thereonduring the transformation period, as set forth, for example, in thecopending application of Eugene J. Houdry, Serial No, 35,101, led August7, 1985, which issued as Patent-No. 2,078,951 on May 4, 1937. Converters42a are preferably conducted and arranged for use alternately on-streamand in regeneration in situ of said catalyst in a manner to permitfeeding of a continuous stream of vreactant material to the battery ofconverters, fresh regenerating medium, such as air or other oxygenbearing material being admitted to the converter orv convertersundergoing regeneration by line 3Ib and valved branch or branches 45h,while spent regenerating medium is vented from valved branch or branches46h and line 4'Ib, respectively.

'I'he residue in line 9, preferably while still hot,

is admitted to a suitable heater such as tubular heater 38h wherein itis raised to reaction ternperature and a substantial portion of itvapor-- ized. In order to assist in such vaporization and to minimizethermal cracking of the residue, as well as to assist in the subsequentcatalytic trans` formation, a suitable inert diluent fluid, such assteam, is admitted to heater 38h, as by line 48h, in amounts whichusually lie within the range of 5 to 25% by weight of the heated charge.

The heatedstream, after rejection therefrom of unvaporized material inseparator 39h, at substantially atmospheric or low superatmosphericpressure, preferably, not in excess of lbs/sq. in. gauge, is passedthrough the contact mass in converters 42b for an operating or runperiodv during which the contact mass is maintained at a temperaturewithin the range of 750 to 925 F.

The reaction products made in either or both of the reaction zones haveremoved from them any and substantially all material which is within theboiling range of thecharge to zone B. One method of effecting suchremoval is by controlled partial condensation while utilizing a heatexchange medium. According to the drawing, vaporous reaction productsleaving zone A, preferably freed of any tar made in that zone, may beconducted by line I0 to line II, containing vaporous reaction productsmade in zone B, and passed, with the latter, through heat exchanger 5into line I2, in heat exchange relation with controlled amounts of coldfresh charge to effect the desired partial condensation. 'I'he resultingmixture of liquid and vapors is conducted through line I2 to separatorI3. The vapors, containing the desired lower boiling hydrocarbonsproduced in both reaction zones leave separator I3 by vapor line I4 vandare conducted to fractionator I to be fractionated with the charge.These vapors may be led by line I4 to line 4 wherein they mix with theheated fresh charge and together with it be admitted to fractionator Iand/or, all or any desired portion of the vapors in line I4 may becondensed and the III) condensate admitted to fractionator I, preferablyat a point above the point of admission of the charge thereto, to serveas a temperature controlling medium after the manner of a refluxingagent to assist in maintaining balanced and controlled operation offractionator I. The condensatefproduced in heat exchanger 5 is withdrawnfrom separator I3 by line I5. This condensate is clean and possessesother characteristics which render it suitable for use as a distillate,domestic or Diesel fuel oil or as a distillate or gas oil crackingstock. If desired, it may have entrained lower boiling hydrocarbonsremoved therefrom in steam stripper I6 provided with steam inlet line I1and vapor outlet line I8 which discharges into vapor line I4. Thestripped condensate leaving the stripper I G by line I9 may be conductedby valved line 20 to reaction zone A to be further converted thereinalong with or as an adjunct to the one or more distillate streamsentering that zone, or all or any desired portion of it may be withdrawnfrom the system by valved line 2| to be used for fuel oil or any otherdesired purpose. may be by-passed by valved line 22 interconnectinglines I5" and I9. It is usually desirable to add additional amounts ofinert diluent fluid to the vapors leaving separator 39h. to insuremaintenance of vapor phase condition in lines 43h, b and in converters2b. Such adition may be up to 10% by weight of steam, as by line 49h.

In a typical operation of the unitary system wherein a 400 F. end pointgasoline is the desired product, a whole petroleum crude, as forexample, an East Texas crude may be continuously charged to fractionatorI and divided therein into straight run gasoline, a heavy naphtha cuthaving a boiling range of the order of 400 to 500 F. issuing therefromby line 6, one or more gas oil` cuts issuing therefrom by lines 1 and/or8 and having an end point of about 650 to r100 F., and a residue,leaving the co1- umn by line 9, containing substantially all portions ofthe crude boiling above the end boiling point of the gas oil. The heavynaphtha may be subjected to the action of a temperature of the order of900 to 930 F. and a pressure of about 1375 lbs./sq. in. gauge for about90 seconds in the upper pyrolytic system in reaction zone A and the gasoil subjected to the action of a temperature of about 890 F. and apressure of about 1750 lbs/sq. in. for about three minutes, namely, inthe second of the pyrolytc units to eiect the desired conversion ofthese fractions. After removal of the heavy tar therefrom as in flashvaporizer 34a, the synthetic crude vapors produced in the pyrolyticunits are vented from zone A into vapor line I0. Meanwhile the residuein line 9 may be admitted to heater 38h and heated to about 890 F.,about 15% by weight of superheated steam being addedto the residueduring the passage through the heater, as by line 48h. The heatedresidue may then traverse separator 39h and be separated therein into avapor fraction and a heavy tar having an A. P. I. gravity of the orderof The vapor fraction under a pressure of the order of 15 lbs./sq. in.gauge may then be admitted to one of the converters 42h and passedthrough a catalyst contained therein and comprising molded pieces ofactivated hydrosilicate of alumina in which the silica to alumina weightratio is of the order of 3/2:1, having incorporated therewith about 1%by weight of an oxide of manganese as a regeneration promoter andmaintained at a temperature Stripper I6 of the order of 860 F. 'I'herate of feed of the vapors to the contact mass may be oi' the order of3:4 (3 volumes of condensed vapors per hour to 4 volumes of contactmass). The catalytic synthetic crude is conducted from reaction zone Bby line Il, and, along with the vapors in line I0, is subjected tocontrolled partial condensation by passing the combined vapors in heatexchange relation with fresh charge in heat exchanger 5 so as to producea liquid fraction containing substantially all portions of the syntheticcrude from both reaction zones which boil above the end boiling point ofthe gas oil cut. 'I'he resulting mixture of liquid and vapor may then bepassed through line I2 to separator I3, from which the vapors containingall lower boiling hydrocarbons present in both synthetic crudes may beconducted by line I4 to line 4 and thence into fractionator I, alongwith heated fresh charge, to be fractionated with the latter. The highboiling condensate in line I5 may be freed of entrained and lowerboiling hydrocarbons, as in steam stripper I6, and withdrawn from thesystem, or, if substantially complete consumption of fresh charge isdesired, such condensate may be conducted through line to the lower unitin pyrolytic zone A to be therein subjected to the action of atemperature of the order of 880 F. and a pressure of the order of1750#/sq. in. gauge for about three minutes. 'I'he synthetic crudeproduced from such condensate after being freed of heavy residue invessel 34a may be discharged into line I0 along with the other pyrolyticsynthetic crudes.

When one of the pyrolytic systems requires cleaning two of the streamsof distillate being fed to zone A may be combined and converted togetherin a single system, thus leaving the one system free for the necessaryshutdown without interrupting the operation of the unitary system. Forexample: if one of two pyrolytic units operating on gas oil cutsrequires cleaning, the charge to these two units may be temporarilycombined and fed to the unit not requiring cleaning, while making anydesired adjustment of the reaction conditions of the unit left inservice; When it becomes necessary to clean a unit acting on the naphthacut the charges to two other two units operating on heavier distillatesmay be combined as above described and the naphtha stream shifted to theunit thus left off Stream.

By the above indicated methods of operation and/or by other methodswhich are slight variations therefrom, it will be apparent to thoseskilled in the art that pyrolytic and catalytic zones A and B,respectively, operate interdependently and simultaneously, with maximumutilization of fresh feed, to produce, from the latter, in desiredproportions, high quality valuable hydrocarbons of the motor fuel orgasoline type, along with valuable higher boiling fuels of distillateand/or residual types. In all instances, pyrolytic Zone A handles onlymaterials which it is capable of acting upon to best advantage, i. e.,clean and easily vaporizable stocks. while catalytic zone B transformsonly virgin or unconverted material.

By the present invention pyrolytic and catalytic reaction zones forproducing high quality lower boiling hydrocarbons from higher boilinghydrocarbons have been combined in a manner that permits each system tooperate at high efflciency and to best advantage. The unitary system,which permits substantial economies of heat and of equipment. alsoprovides for flexibility of operation that allows for yields of lowerand higher boiling fuels in proportions suitable for meeting current andlocal refinery and market conditions of supply and demand. 'I'hisflexibility is realized with maximum utilization of fresh feed to thesystem. Furthermore, while maintaining the above advantages, the unitarysystem provides for production of lower boiling hydrocarbons of highquality, including the ease with which they can be refined, regardlessof the characteristics of the original charge.

It is to be understood that the drawing and explanation thereof are onlyexemplary of the invention. Many minor variations in the equipment andthe operation will be apparent to one skilled in the art. Suchvariations are embraced within the scope of the invention and -includeamong other considerations, various known or desired methods ofcontrolling the temperatures of one or more of the various streams offluid in the system for purposes of realizing heat and other economies.For example, fresh charge may be utilized to control the temperature ofthe pyrolytic synthetic crude entering the iiash chambers of thepyrolytic zone and/or for controlling the temperature of either or bothof the fractions leaving such flash chambers. 'Ihe invention isapplicable; also when a suitable viscosity breaking unit or process isused as an adjunct to the vaporizer 38h for the bottoms cut of freshcharging stock. Vaporizer 38h and separator 39h may be replaced by acontact vaporizer, such for example, as that disclosed in U. S. PatentNo. 1,989,927, issued to Eugene J. Houdry on February 5, 1935, or asdisclosed in the copending Houdry application, Serial No. 32,170, ledJuly 19, 1935.

'I'he present invention is, in some respects, generally related to mycopending applications Serial Nos. 111,780 and 116,699, filed November20, 1936 and December 19, 1936, respectively. It is directed, however,to specific features of process and apparatus not involved or claimed inthese copending applications, including features for controlling thecharacteristics of charging material fed to and reaction productsobtained from separate pyrolytic and catalytic conversion zones. One ofthe salient features of the present invention, which distinguishes itfrom the inventions set forth and claimed in the aforesaid copendingapplications, relates to interdependent conversion systems and processfor operating such systems involving the use of a single fractionatingzone for handling both charging material and regulated portions of thereaction products. Further distinctions will be apparent upon referenceto the claims in this and the said copending applications.

I claim as my invention:

1. In the production of lower boiling hydrocarbons of the motor fueltype, the process comprising feeding to a fractionating zone a chargingstock comprising easily vaporizable and diilcultly vaporizable higherboiling hydrocarbons, removing from said zone a distillate cut and aresidual fraction, said residual fraction containing diflicultlyvaporizable higher boiling hydrocarbons, subjecting said distillate cutto conditions of'pyrolytic conversion to produce therefrom desired lowerboiling hydrocarbons of the motor fuel type, subjecting said residualfraction to catalytic cracking conditions including the use of a solidadsorptive contact mass ',capable of promoting cracking reactions toproduce from said fraction desired lower boiling hydrocarbons of themotor fuel type.' separating from products of the pyrolytic 'andcatalytic reactions hydro--l carbons boiling within the boiling range ofsaid residual fraction, feeding reaction products remaining after saidseparation to said fractionating zonevto be fractionated Itherein alongwith said charging stock, removing a motor fuel fraction of controlledend point from said fractionating zone, subjecting the separatedfraction of said products to separate pyrolytic cracking to producelower boiling hydrocarbons of the motor fuel type, and fractionatingproducts of the last named cracking step in said fractionating zonealong with said charging stock and'said remaining catalytic andpyrolytic products.

2. In the production of lower boiling hydrocarbons of the motor fueltype from a wide boiling range composite hydrocarbon starting materialcontaining botheasily vaporizable and diillcultly vaporizablehydrocarbons which are above the gasoline boiling range, the steps ofprocess which comprise introducing said starting material into afractionating zone, thereinA separating said material into at least twofractions of different boiling range characteristics, a lower boiling ordistillate fraction and a higher boiling or residual fraction, saidlower boiling fraction being composed primarily of hydrocarbons higherboiling than gasoline, including components within the gas oil boilingrange, and said higher boiling or residual fraction containingsubstantially all of the diflicultly vaporizable portions of saidstarting material, heating and feeding at least a substantial portion ofsaid residual fraction, primarily in vapor phase, to a confined reactionzone containing a solid adsorptive, substantially incombustible crackingcatalyst and maintained under conditions so as to eiiect a conversion orcracking of said higher boiling or residual fraction to substantialextent into lower boiling hydrocarbons of the 'motor fuel type, passingthe aforesaid lower boiling or distillate fraction through a secondconfined reaction zone while maintaining the same under conditions'capable of effecting a pyrolytic conversion thereof to substantialextent into lower boiling hydrocarbons ofthe motor fuel type, passing aportion only of the reaction products issuing from said reaction zonesinto 'the aforesaid fractionating zone, therein to be fractionated inadmixture with the aforesaid hydrocarbon starting material, said portionof said products beingof controlled boiling range and comprisingsubstantially only hydrocarbons boiling below the boiling range of theaforesaid higher boiling or residual fraction, and withdrawing from saidfractionating zone a blend of 'lower boiling hydrocarbons within themotor fuel range produced in both said pyrolytic and catalytic reactionzones.

3. In the production oflower boiling hydrocarbons of the motor'fuel typefrom a high boiling composite hydrocarbon starting materialof wideboiling or residual fraction containing substantially all of thediiilcultly vaporizable portions of said starting material, heating andfeeding at least a substantial portion of said residual fraction,primarily in vapor phase, to a confined reaction zone containing asolid, adsorptive, substantially incombustible catalytic material andmaintained under conditions so as to effect a catalytic conversion orcracking of said higher boiling or residual fraction to substantialextent into lowerl boiling hydrocarbons of the motor fuel type, passingthe aforesaid lower boiling or distillate fraction through a secondconfined reaction zone maintained under conditions capable of effectinga pyrolytic conversion of the same to substantial extent into lowerboiling hydrocarbons of the motor fuel type, separating higher boilinghydrocarbons within the range of the aforesaid residual fraction fromremaining cornponents of the products of reaction issuing from saidpyrolytic and catalytic reaction zones, blending lower boiling reactionproducts remaining after said separation with said starting material,and separating from the resulting blend a lower boiling motor fuel ofcontrolled end point While simultaneously producing the aforesaiddistillate and residual fractions.

4. In the production of lower boiling hydrocarbons of the motor fueltype, the process of establishing in simultaneous, cooperative andinterdependent operating relation a pyrolytic reaction zone and acatalytic reaction zone, each of said zones being capable of and adaptedto effect conversion of higher boiling hydrocarbons into lower boilinghydrocarbons, and a single fractionating zone, in the lattercontinuously dividing a composite hydrocarbon material containing botheasily vaporizable and difficulty vaporizable higher boilinghydrocarbons into at least one clean higher boiling distillate fractionand a residual fraction containing substantially all the difficultyvaporizable portions of the charge, feeding said distillate fraction tosaid pyrolytic zone while maintaining the latter under suitableconditions to effect thermal conversion of said distillate into lowerboiling hydrocarbons, vaporizing a substantial proportion of saidresidual fraction and charging the resulting vapors, substantially freeof unvaporized liquids and of extraneous reactant gases, to saidcatalytic zone maintained under conditions favorable to the productionfrom said residue of high antiknock lower boiling hydrocarbons, andadsorptive silicious catalytic material being maintained within saidcatalytic zone, removing the reaction products from each of said zones,separating from said reaction products substantially al1 hydrocarbonswithin the boiling range of said residual fraction, feeding theremainder of said reaction products to said fractionating zone to befractionated along with said charge, removing from said fractionatingzone a blend of the aforementioned lower boiling hydrocarbons of themotor fuel type, and feeding the higher boiling hydrocarbons separatedfrom said reaction products to said pyrolytic zone to be thereinconverted into lower boiling hydrocarbons.

5. In the production of lower boiling hydrocarbons of the motor fueltype from a high boiling composite hydrocarbon starting materialcontaining both easily vaporizable and dlilicultly vaporizablehydrocarbons which are above the gasoline boiling range, the steps ofprocess which comprise introducing said starting material into afractionating zone, therein separating said starting material into atleast two fractions of different boiling range characteristics, a lowerboiling or distillate fraction and a higher boiling or residualfraction, said lower boiling fraction being composed predominantly ofhydrocarbons higher boiling than gasoline, including components withinthe gas oil boiling range. and said higher boiling or residual fractioncontaining substantially all of the diiculty vaporizable portions ofsaid starting material, heating said residual hydrocarbon fraction andseparating tarry components having a gravity of the order of 15 A. P. I.from the remaining portions thereof, feeding the last-mentioned orremaining portions, primarily in vapor phase, to a confined reactionzone containing a solid adsorptive silicious cracking catalyst andmaintained under conditions to effect a catalytic cracking ortransformation of the said remaining portions of said residual fractionto substantial extent into lower boiling hydrocarbons including asubstantial prol portion of components within the gasoline boilingrange, passing the aforesaid lower boiling or distillate fractionthrough a second confined reaction zone while maintaining the same underconditions capable of effecting a pyrolytic conversion thereof tosubstantial extent into lower boiling hydrocarbons of the motor fueltype, passing products of reaction issuing from each of said confinedzones having a boiling range below that of the aforesaid higher boilingor residual fraction into the aforesaid fractionating zone, thereby tobe fractionated in admixture with the aforesaid hydrocarbon startingmaterial, and withdrawing from said fractionating zone a blend of lowerboiling hydrocarbons composed largely of components within the gasolineboiling range produced in both said pyrolytic and catalytic conversionzones.

6. In the production of lower boiling hydrocarbons of the motor fueltype, the process of establishing in continuous cooperative andinterdependent operating relation pyrolytic reaction zones, a singlefractionating zone, and at least one catalytic reaction zone containingregenerative silicious contact material capable of promotingtransformation of higher boiling hydrocarbons into lower boilinghydrocarbons, heating to distillation temperature a compositehydrocarbon charging material having substantially the boiling rangecharacteristics of a whole crude petroleum oil, feeding said heatedcharge to said fractionating zone, withdrawing from the latter a heavynaphtha fraction, at least one gas oil fraction and a liquiddistillation residual fraction, separately converting said naphtha andgas oil fractions into lower boiling hydrocarbons in individual ones ofsaid pyrolytic zones, effecting vaporization of a substantial portion ofsaid residual fraction, passing the resulting vapors through saidsilicious contact material within said catalytic reaction zone whilemaintaining the latter at a temperature within the range of '750 F. to925 F. to convert such vapors to substantial extent into lower boilinghydrocarbons, withdrawing reaction products from said pyrolytic andcatalytic reaction zones, combining said pyrolytic and catalyticreaction products, removing from the combined products substantially allhydrocarbons boiling within the range of said residual fraction,admitting the remainder of said combined products to said fractionatingzone to be therein fractionated along with said charge, and withdrawingas product from said fractionating zone a blend of substantially all thedesired end point lower boiling hydrocarbons produced in said catalyticand pyrolytic reaction zones.

7. In the production of valuable lower boiling hydrocarbons of the motorfuel type, the process of heating to distillation temperature acomposite hydrocarbon starting material containing a mixture of botheasily vaporizable hydrocarbons of the distillate fuel type and morediflicultly vaporizable hydrocarbons of the residual fuel type, feedingthe heated mixture to a fractionating zone, withdrawing from said zone aplurality of distillate fractionns of differing boiling ranges andhigher boiling than the aforementioned motor fuel, and a bottomsfraction containing approximately all of the hydrocarbons in saidst'arting material which boil above 750 F. including said difilcultlyvaporizable hydrocarbons, heating and vaporizing a substantialproportion of said bottoms fraction land feeding the resulting heatedvapors to a reaction zone containing a solid, adsorptive catalyticmaterial, comprising essentially a blend of silica and alumina, toeffect transformation of said vapors into high antiknock lower boilinghydrocarbons, withdrawing reaction products from said catalytic zone andintroducing a substantial proportion of said products boiling below theboiling range of said bottoms fraction into said fractionating zone tobe therein fractionated along with said starting material, feeding saiddistillate fractions from said fractionating zone to separate respectivereaction zones, each maintained under conditions so as to eiectpyrolytic conversion of said distillate fractions into lower boilinghydrocarbons, withdrawing reaction products from the aforementionedpyrolytic reaction zones, removing from the last-mentioned reactionproducts substantially all hydrocarbons higher boiling than the highestboiling of said distillate fractions, ad-

mitting the remainder of said last-mentioned reaction products to saidfractionating zone to be therein fractionated along with saidhydrocarbon starting material and products from said catalytic reactionzone, and withdrawing from said fractionating zone lower boilinghydrocarbons of the motor fuel type comprising a blend of hydrocarbonsproduced in both the catalytic and pyrolytic reaction zones.

8. In apparatus for producing lower boiling hydrocarbons from chargingmaterial containing both easily vaporizable and diflicultly vaporizablehigher boiling hydrocarbons, in combination, a heater for fresh charge,a fractionating column connected to said heater and adapted to eiectseparation of lower boiling hydrocarbons from higher boilinghydrocarbons and to divide the latter into at least one distillatefraction and a residual fraction', a catalytic transformation systemconnected to said column so'as to re,

ceive said residual fraction, said catalytic system comprising heatingmeans for producing hydrocarbon vapors from said residue, a plurality ofconverters selectively connected to said heating means and containing abed of regenerative, adsorbent silicious contact mass, said convertersbeing adapted and arranged for use alternately in the transformation ofhydrocarbons and in regeneration of said mass in place, a pyrolyticconversion system adapted to receive said distillate fraction from theaforesaid column and providing heating and converting means therefor,means for conducting reaction products from each of said systems to saidfractionating column, and means associated with said last named meansfor separating and removing the highest boiling components of saidreactionA products from the latter.

9. In apparatus for producing lower boiling hydrocarbons from chargingmaterial containing both easily vaporizable and diilicultly vaporizablehigher boiling hydrocarbons, in combination, a heater for fresh charge,a fractionating column connected to said heater and adapted to eiectseparation of lower boiling hydrocarbons from higher boilinghydrocarbons and to divide the latter into at least one distillatefraction and a residual fraction, a catalytic transformation systemconnected to said column so as to receive said residual fraction, saidcatalytic system comprising heating means for producing hydrocarbonvapors from said residue, a plurality of converters selectivelyconnected to said heating means and containing a body of regenerative,adsorbent contact mass in the form of small pieces of regular sizes andshapes, said converters being adapted and arranged for use alternatelyin the transformation of hydrocarbons and in regeneration of said massin place, a pyrolytic conversion system adapted to receive saiddistillate fraction and providing heating and converting means therefor,means associated with said pyrolytic system for separating and removingfrom the pyrolytic reaction products substantially all hydrocarbonshigher boiling than said distillate fraction to leave a vapor fractioncomprising essentially hydrocarbons lower boiling than said residualfraction, means for conducting said vapor fraction to said fractionatingcolumn, means for conducting catalytic reaction products from saidcatalytic system, means for separating and removing as liquid from saidcatalytic reaction products substantially all hydrocarbons higherboiling than said distillate fraction to leave a vapor fractioncomprising essentially hydrocarbons lower boiling than said residualfraction, means for conducting said last named vapor fraction to saidfractionating column, and means for conducting said last named liquidfraction to said pyrolytic system.

10. In apparatus for producing lower boiling hydrocarbons from chargingmaterial containing easily vaporizable and diillcultly vaporizablehigher boiling hydrocarbons, in combination, a heater for heating freshcharge to distillation temperature, a fractionating column' providedwith an inlet connection, an overhead vapor outlet connection for lowerboiling hydrocarbons, at least two side stream distillate connectionsfor higher boiling hydrocarbon fractions of relatively higher andrelatively lower boiling ranges and an outlet for distillation residue,a connection from said heater to said inlet connection, at least twopyrolytic conversion systems, a connection between said side streamconnection for relatively lower boiling range distillate and one of saidsystems, a connection between the other of said side stream connectionsand another pyrolytic system, a catalytic transformation systemcomprising a heater for effecting vaporization of a substantial portionof said distillation residue, a separator connected to said last namedheater for removing unvaporized material from vapors leaving said heaterand providing an overhead vapor connection, and a plurality ofconverters selectively connected to said separator through said lastnamed vapor connection, said converters containing a regenerativecontact mass comprising essentially a blend of silica and alumina inmolded form and being adapted for use alten' nately in transformation ofhydrocarbons and in regeneration in place, a connection between saidresidue outlet connection and said last named heater, lines forconducting reaction products from said catalytic system, lines forwithdrawing pyrolytic reaction products i'rom each pyrolytic system,means including separating means associated with said pyrolytic systemsand with said catalytic system for receiving reaction products therefromand separating from said reaction products as liquid substantially allhydrocarbons issuing from said systems which are as high boiling as saidhighest boiling distillate fraction, and vapor connections between saidseparating means and said fractionating column for conducting theremainder of the reaction products into said column.

l1. In apparatus for producing lower boiling hydrocarbons from chargingmaterial containing both easily vaporizable and diiilcultly vaporizablehigher boiling hydrocarbons, in combination, a' heater for fresh charge,a fractionating column connected to said heater and adapted to eiectseparation of lower boiling hydrocarbons from higher boilinghydrocarbons and to divide the latter into a plurality of distillatefractions and a residual fraction, a catalytic transformation systemconnected to said column so as to receive said residual fraction, saidcatalytic systemV comprising heating means for producing hydrocarbonvapors from said residue, a plurality of converters selectivelyconnected to said heating means and containing regenerative, adsorbentsilicious contact mass, said converters being adapted and arranged foruse alternately in the transformation of hydrocarbons and inregeneration of said mass in place, a plurality of pyrolytic conversionsystems, each one of said pyrolytic systems being connected to saidfractionating column so as selectively to receive any one or any desiredcombination of said distillate fractions, means for removing from thereaction products made in any of said systems hydrocarbons boilingwithin the boiling range of said residue, and means for conducting theremainder of said products from the last-mentioned means to saidfractionating column.

ARTHUR E. PEW, Ja.

CERTIFICATE OF CORRECTION. l Patent No. 2,197,009. `April 16, 191m.

- ARTHUR E. PEw, JR.

It is hereby certified that 4error' appears in the printed specificationof the above numbered patent requiring correction as follows: Page l,second column, line 2l, for "charactertstics" read characteristicsugpage 2, first column, line T5, for the word "exchangers" read exchanger;page Il, first column, line 5C, for "adition" read --addition; page 6,first column, lines 58 and )42, claim )4, and second column, line 9,claim 5, for "difficulty" read -difficultly-'; page Y, first column,line l5 claim Y, for "fractionns" read --fractions; and that -the saidLetters Patent should be read with this correction therein that the samemay conform to the record of the case in the Patent Office.-

Signed and sealed this 18th day of June, A. D. 19140 Henry Van Arsdale(Seal) Acting Commissioner of Patents.

